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The Weinschel Associates DA series of digital attenuators represents the latest in programmable attenuator technology. The DA attenuator architecture combines the rugged design and superior performance expected of Weinschel Associates products with modern technology to achieve the ease of integration and price performance expected in a plug-and-play marketplace. The DA family of attenuators is targeted toward a multitude of commercial and military applications, including test instrumentation, base station infrastructure, broadband telecommunications, microwave and VSAT radios, and radar systems.

The DA product line is structured to offer broadband frequency coverage (DC to 6 GHz and DC to 13 GHz versions), in a selection of attenuation ranges (30, 60 and 90 dB), all with a 0.5 dB step size. The attenuators feature the high accuracy, repeatability, and fast switching speeds (< 100 ns) of a digital solution as well as a power rating of 0.3 W CW ( +25 dBm) to enable their integration into a broad spectrum of applications. Tables 1 and 2 delineate the current offerings in the DA product family along with the insertion loss for each model versus frequency. Rounding out the performance features of the DA product line are a +22 dBm 0.1 dB compression point, a +32 dBm third-order intercept point and a maximum phase shift with change in attenuation of 1 degree per dB x f (GHz).

Table 1 DA Product Family with Attenuation Range Values

Table 2 DA Product Family with Insertion Loss Values

Ease of use has been addressed through the implementation of a standard USB 2.0 interface and the inclusion of a user friendly software application and device driver. The unit draws its power from the USB interface eliminating the need for an external power source. The DA Controller software (see Figure 1) searches out available serial (COM) ports on the host computer and presents those in a drop down list. The provided device driver recognizes when a DA series attenuator is installed on a USB port and creates a virtual COM port that will appear on the list. Once the port is selected, the slider and/or increment/decrement box may be used to control the DA directly.

Figure 1 Digital attenuator control widget.

If the user prefers to integrate the control of the DA into a National Instruments (NI) LabView application or a proprietary application, WA will provide a library (dll) file for inclusion. Custom software solutions and support are also available.

Again, the objective of the Digital Attenuator User Interface is simplicity. The DA product line effectively eliminates the need for expensive and complicated hardware and software interfaces, allowing the user to easily and cost-effectively implement the programmable attenuator function in their RF chain.